Substituted thiazolo[4,5-d]pyrimidin-2(3H)-one

ABSTRACT

A compound of formula (I) and pharmaceutically acceptable salts or solvates thereof for use in therapy.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the national phase application under 35 U.S.C. § 371of PCT International Application No. PCT/GB2003/003998, filed Sep. 16,2003, which claims priority to United Kingdom Application Serial No.0221828.7, filed Sep. 20, 2002.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT

Not Applicable.

INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC

Not applicable.

The present invention relates to a thiazolopyrimidinone compound,processes and intermediates used in its preparation, pharmaceuticalcompositions containing it and its use in therapy.

Chemokines play an important role in immune and inflammatory responsesin various diseases and disorders, including asthma and allergicdiseases, as well as autoimmune pathologies such as rheumatoid arthritisand atherosclerosis. These small secreted molecules are a growingsuperfamily of 8-14 kDa proteins characterised by a conserved fourcysteine motif. At the present time, the chemokine superfamily comprisesthree groups exhibiting characteristic structural motifs, the Cys-X-Cys(C—X—C), Cys-Cys (C—C) and Cys-X₃-Cys (C—X₃—C) families. The C—X—C andC—C families have sequence similarity and are distinguished from oneanother on the basis of a single amino acid insertion between theNH-proximal pair of cysteine residues. The C—X₃—C family isdistinguished from the other two families on the basis of having atriple amino acid insertion between the NH-proximal pair of cysteineresidues.

The C—X—C chemokines include several potent chemoattractants andactivators of neutrophils such as interleukin-8 (IL-8) andneutrophil-activating peptide 2 (NAP-2).

The C—C chemokines include potent chemoattractants of monocytes andlymphocytes but not neutrophils. Examples include human monocytechemotactic proteins 1-3 (MCP-1, MCP-2 and MCP-3), RANTES (Regulated onActivation, Normal T Expressed and Secreted), eotaxin and the macrophageinflammatory proteins 1α and 1β (MIP-1α and MIP-1β).

The C—X₃—C chemokine (also known as fractalkine) is a potent chemoattractant and activator of microglia in the central nervous system(CNS) as well as of monocytes, T cells, NK cells and mast cells.

Studies have demonstrated that the actions of the chemokines aremediated by subfamilies of G protein-coupled receptors, among which arethe receptors designated CCR1, CCR2, CCR2A, CCR2B, CCR3, CCR4, CCR5,CCR6, CCR7, CCR8, CCR9, CCR10 and CCR11 (for the C—C family); CXCR1,CXCR2, CXCR3, CXCR4 and CXCR5 (for the C—X—C family) and CX₃CR1 for theC—X₃—C family. These receptors represent good targets for drugdevelopment since agents which modulate these receptors would be usefulin the treatment of disorders and diseases such as those mentionedabove.

BACKGROUND OF THE INVENTION

WO-01/25242 discloses a series of thiazolopyrimidinone compounds usefulas CXCR2 antagonists. A compound within the scope of WO-01/25242, butnot specifically disclosed therein, has now surprisingly been found tohave an improved pharmacological profile when compared with thestructurally most similar compounds from WO-01/25242 i.e. Examples 4 and7.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

Not applicable.

DETAILED DESCRIPTION OF THE INVENTION

The present invention therefore provides a compound of formula (I) andpharmaceutically acceptable salts or solvates thereof:

The compound of formula (I) is capable of existing in tautomeric form.Tautomers and mixtures thereof also form an aspect of the presentinvention.

According to the invention there is also provided a process for thepreparation of compound (I) which comprises reaction of a compound offormula (II):

where R is C₁₋₆ alkyl with an acid,

and optionally thereafter: forming a pharmaceutically acceptable salt.

Preferably R is ethyl or methyl, more preferably methyl. Preferably thereaction is carried out using dioxan and HCl. Preferably the compoundsof the invention are prepared according to the procedures exemplifiedherein.

The compound (II) can be prepared from the corresponding compound offormula (III):

where R² is halogen by treating with a compound ROH in the presence of abase. Preferably the compound of formula (III) is treated with sodiummethoxide. Preferably R² is chloro.

Compounds of formula (III) can be prepared using the sequence below:

Suitable reagents for steps a to f will be known to those skilled in theart. Preferably steps a to f are carried out as exemplified herein.

The compound of formula (II) is itself believed to be novel and forms afurther aspect of the invention.

It will be appreciated by those skilled in the art that in the processesof the present invention certain functional groups such as hydroxyl oramino groups in the starting reagents or intermediate compound may needto be protected by protecting groups. Thus, the preparation of thecompound of formula (I) may involve, at an appropriate stage, theremoval of one or more protecting groups. The protection anddeprotection of functional groups is fully described in ‘ProtectiveGroups in Organic Chemistry’, edited by J. W. F. McOmie, Plenum Press(1973), and ‘Protective Groups in Organic Synthesis’, 2nd edition, T. W.Green & P. G. M. Wuts, Wiley-Interscience (1991).

The compound of formula (I) above may be converted to a pharmaceuticallyacceptable salt or solvate thereof, preferably a basic addition saltsuch as sodium, potassium, calcium, aluminium, lithium, magnesium, zinc,benzathine, chloroprocaine, choline, diethanolamine, ethanolamine,ethyldiamine, meglumine, tromethamine or procaine, or an acid additionsalt such as a hydrochloride, hydrobromide, phosphate, acetate,fumarate, maleate, tartrate, citrate, oxalate, methanesulphonate orp-toluenesulphonate.

The compound of formula (I) has activity as a pharmaceutical, inparticular as a modulator of chemokine receptor (especially CXCR2)activity, and may be used in the treatment (therapeutic or prophylactic)of conditions/diseases in human and non-human animals which areexacerbated or caused by excessive or unregulated production ofchemokines. Examples of such conditions/diseases include:

-   -   (1) (the respiratory tract) obstructive airways diseases        including chronic obstructive pulmonary disease (COPD); asthma,        such as bronchial, allergic, intrinsic, extrinsic and dust        asthma, particularly chronic or inveterate asthma (e.g. late        asthma and airways hyper-responsiveness); bronchitis; acute,        allergic, atrophic rhinitis and chronic rhinitis including        rhinitis caseosa, hypertrophic rhinitis, rhinitis purulenta,        rhinitis sicca and rhinitis medicamentosa; membranous rhinitis        including croupous, fibrinous and pseudomembranous rhinitis and        scrofoulous rhinitis; seasonal rhinitis including rhinitis        nervosa (hay fever) and vasomotor rhinitis; sarcoidosis,        farmer's lung and related diseases, fibroid lung and idiopathic        interstitial pneumonia;    -   (2) (bone and joints) rheumatoid arthritis, seronegative        spondyloarthropathies (including ankylosing spondylitis,        psoriatic arthritis and Reiter's disease), Behcet's disease,        Sjogren's syndrome and systemic sclerosis;    -   (3) (skin) psoriasis, atopical dermatitis, contact dermatitis        and other eczmatous dermitides, seborrhoetic dermatitis, Lichen        planus, Pemphigus, bullous Pemphigus, Epidermolysis bullosa,        urticaria, angiodermas, vasculitides, erythemas, cutaneous        eosinophilias, uveitis, Alopecia areata and vernal        conjunctivitis;    -   (4) (gastrointestinal tract) Coeliac disease, proctitis,        eosinopilic gastro-enteritis, mastocytosis, Crohn's disease;        ulcerative colitis, indeterminate colitis, microscopic colitis,        inflammatory bowel disease, irritable bowel syndrome,        non-inflammatory diarrhea, food-relate allergies which have        effects remote from the gut, e.g., migraine, rhinitis and        eczema;    -   (5) (central and peripheral nervous system) Neurodegenerative        diseases and dementia disorders, e.g. Alzheimer's disease,        amyotrophic lateral sclerosis and other motor neuron diseases,        Creutzfeldt-Jacob's disease and other prion diseases, HIV        encephalopathy (AIDS dementia complex), Huntington's disease,        frontotemporal dementia, Lewy body dementia and vascular        dementia; polyneuropathies, e.g. Guillain-Barré syndrome,        chronic inflammatory demyelinating polyradiculoneuropathy,        multifocal motor neuropathy, plexopathies; CNS demyelination,        e.g. multiple sclerosis, acute disseminated/haemorrhagic        encephalomyelitis, and subacute sclerosing panencephalitis;        neuromuscular disorders, e.g. myasthenia gravis and        Lambert-Eaton syndrome; spinal disorders, e.g. tropical spastic        paraparesis, and stiff-man syndrome: paraneoplastic syndromes,        e.g. cerebellar degeneration and encephalomyelitis; CNS trauma;        migraine; and stroke.    -   (6) (other tissues and systemic disease) Atherosclerosis,        Acquired Immunodeficiency Syndrome (AIDS), lupus erythematosus,        systemic lupus, erythematosus, Hashimoto's thyroiditis, type I        diabetes, nephrotic syndrome, eosinophilia fascitis, hyper IgE        syndrome, lepromatous leprosy, and idiopathic thrombocytopenia        pupura; post-operative adhesions, and sepsis.    -   (7) Stroke, subarachnoid haemorrage, re-perfusion injury in the        heart, brain, peripheral limbs and other organs.    -   (8) (allograft rejection) acute and chronic following, for        example, transplantation of kidney, heart, liver, lung, bone        marrow, skin and cornea; and chronic graft versus host disease;    -   (9) Cancers, especially non-small cell lung cancer (NSCLC),        malignant melanoma, prostate cancer and squamous sarcoma, and        tumour metastasis;    -   (10) Diseases in which angiogenesis is associated with raised        CXCR2 chemokine levels (e.g. NSCLC, diabetic retinopathy).    -   (11) Cystic fibrosis    -   (12) Burn wounds & chronic skin ulcers    -   (13) Reproductive Diseases (e.g. Disorders of ovulation,        menstruation and implantation, Pre-term labour, Endometriosis)

Thus, the present invention provides a compound of formula (I), or apharmaceutically-acceptable salt or solvate thereof, as hereinbeforedefined for use in therapy.

Preferably the compound of the invention is used to treat diseases inwhich the chemokine receptor belongs to the CXC chemokine receptorsubfamily, more preferably the target chemokine receptor is the CXCR2receptor,

Particular conditions which can be treated with the compound of theinvention are rheumatoid arthritis, diseases in which angiogenesis isassociated with raised CXCR2 chemokine levels, and COPD. It is preferredthat the compound of the invention is used to treat rheumatoid arthritisand respiratory disease.

As a further aspect of the present invention, the compound of formula(I) may have utility as an antagonist of the CX3CR1 receptor. Such acompound is expected to be particularly useful in the treatment ofdisorders within the central and peripheral nervous system and otherconditions characterized by an activation of microglia and/orinfiltration of leukocytes (e.g. stroke/ischemia and head trauma).

In a further aspect, the present invention provides the use of acompound of formula (I), or a pharmaceutically acceptable salt orsolvate thereof, as hereinbefore defined in the manufacture of amedicament for use in therapy.

In a still further aspect, the present invention provides the use of acompound of formula (I), or a pharmaceutically acceptable salt orsolvate thereof, as hereinbefore defined in the manufacture of amedicament for the treatment of human diseases or conditions in whichmodulation of chemokine receptor activity is beneficial.

In the context of the present specification, the term “therapy” alsoincludes “prophylaxis” unless there are specific indications to thecontrary. The terms “therapeutic” and “therapeutically” should beconstrued accordingly.

The invention still further provides a method of treating a chemokinemediated disease wherein the chemokine binds to a chemokine (especiallyCXCR2) receptor, which comprises administering to a patient atherapeutically effective amount of a compound of formula (I), or apharmaceutically acceptable salt or solvate thereof, as hereinbeforedefined.

The invention also provides a method of treating an inflammatorydisease, especially rheumatoid arthritis, COPD, respiratory disease andpsoriasis, in a patient suffering from, or at risk of, said disease,which comprises administering to the patient a therapeutically effectiveamount of a compound of formula (I), or a pharmaceutically acceptablesalt or solvate thereof, as hereinbefore defined.

For the above-mentioned therapeutic uses the dosage administered will,of course, vary with the compound employed, the mode of a distribution,the treatment desired and the disorder indicated.

The compound of formula (I) and pharmaceutically acceptable salts andsolvates thereof may be used on their own but will generally beadministered in the form of a pharmaceutical composition in which theformula (I) compound/salt/solvate (active ingredient) is in associationwith a pharmaceutically acceptable adjuvant, diluent or carrier.Depending on the mode of administration, the pharmaceutical compositionwill preferably comprise from 0.05 to 99% w (per cent by weight), morepreferably from 0.05 to 80% w, still more preferably from 0.10 to 70% w,and even more preferably from 0.10 to 50% w, of active ingredient, allpercentages by weight being based on total composition.

The present invention also provides a pharmaceutical compositioncomprising a compound of formula (I), or a pharmaceutically acceptablesalt or solvate thereof, as hereinbefore defined, in association with apharmaceutically acceptable adjuvant, diluent or carrier.

The invention further provides a process for the preparation of apharmaceutical composition of the invention which comprises mixing acompound of formula (I), or a pharmaceutically acceptable salt orsolvate thereof, as hereinbefore defined, with a pharmaceuticallyacceptable adjuvant, diluent or carrier.

The pharmaceutical compositions may be administered topically (e.g. tothe lung and/or airways or to the skin) in the form of solutions,suspensions, heptafluoroalkane aerosols and dry powder formulations; orsystemically, e.g. by oral administration in the form of tablets,capsules, syrups, powders or granules, or by parenteral administrationin the form of solutions or suspensions, or by subcutaneousadministration or by rectal administration in the form of suppositoriesor transdermally. Preferably the compound of the invention isadministered orally.

The invention further relates to combination therapies wherein acompound of formula (1) or a pharmaceutically acceptable salts, solvateor in vivo hydrolysable ester thereof, or a pharmaceutical compositionor formulation comprising a compound of formula (1) is administeredconcurrently or sequentially with therapy and/or an agent for thetreatment of any one of asthma, allergic rhinitis, cancer, COPD,rheumatoid arthritis, psoriasis, inflammatory bowel disease, irritablebowel syndrome, ostearthitis or osteoporosis.

In particular, for the treatment of the inflammatory diseases rheumatoidarthritis, psoriasis, inflammatory bowel disease, irritable bowelsyndrome, COPD, asthma and allergic rhinitis the compounds of theinvention may be combined with agents such as TNF-α inhibitors such asanti-TNF monoclonal antibodies (such as Remicade, CDP-870 andD.sub2.E.sub7.) and TNF receptor immunoglobulin molecules (such asEnbrel.reg.), non-selective COX-1/COX-2 inhibitors (such as piroxicam,diclofenac, propionic acids such as naproxen, flubiprofen, fenoprofen,ketoprofen and ibuprofen, fenamates such as mefenamic acid,indomethacin, sulindac, apazone, pyrazolones such as phenylbutazone,salicylates such as aspirin), COX-2 inhibitors (such as meloxicam,celecoxib, rofecoxib, valdecoxib and etoricoxib) low dose methotrexate,lefunomide; ciclesonide; hydroxychloroquine, d-penicillamine, auranofinor parenteral or oral gold. For inflammatory bowel disease and irritablebowel disorder further convenient agents include sulphasalazine and5-ASAs, topical and systemic steroids, immunomodulators andimmunosuppressants, antibiotics, probiotics and anti-integrins.

The present invention still further relates to the combination of acompound of the invention together with a leukotriene biosynthesisinhibitor, 5-lipoxygenase (5-LO) inhibitor or 5-lipoxygenase activatingprotein (FLAP) antagonist such as zileuton; ABT-761; fenleuton;tepoxalin; Abbott-79175; Abbott-85761;N-(5-substituted)-thiophene-2-alkylsulfonamides; 2,6-di-tert-butylphenolhydrazones; methoxytetrahydropyrans such as Zeneca ZD-2138; the compoundSB-210661; pyridinyl-substituted 2-cyanonaphthalene compounds such asL-739,010; 2-cyanoquinoline compounds such as L-746,530; indole andquinoline compounds such as MK-591, MK-886, and BAY x 1005.

The present invention still further relates to the combination of acompound of the invention together with a receptor antagonist forleukotrienes LTB.sub4., LTC.sub4., LTD.sub4., and LTE.sub4. selectedfrom the group consisting of the phenothiazin-3-ones such as L-651,392;amidino compounds such as CGS-25019c; benzoxalamines such as ontazolast;benzenecarboximidamides such as BIIL 284/260; and compounds such aszafirlukast, ablukast, montelukast, pranlukast, verlukast (MK-679),RG-12525, Ro-245913, iralukast (CGP 45715A), and BAY x 7195.

The present invention still further relates to the combination of acompound of the invention together with a PDE4 inhibitor includinginhibitors of the isoform PDE4D.

The present invention still further relates to the combination of acompound of the invention together with a antihistaminic H.sub1.receptor antagonists such as cetirizine, loratadine, desloratadine,fexofenadine, astemizole, azelastine, and chlorpheniamine.

The present invention still further relates to the combination of acompound of the invention together with a gastroprotective H.sub2.receptor antagonist.

The present invention still relates to the combination of a compound ofthe invention together with an α.sub1.- and α.sub2.-adrenoceptor agonistvasoconstrictor sympathomimetic agent, such as propylhexedrine,phenylephrine, phenylpropanolamine, pseudoephedrine, naphazolinehydrochloride, oxymetazoline hydrochloride, tetrahydrozolinehydrochloride, xylometazoline hydrochloride, and ethylnorepinephrinehydrochloride.

The present invention still further relates to the combination of acompound of the invention together with anticholinergic agents such asipratropium bromide; tiotropium bromide; oxitropium bromide;pirenzepine; and telenzepine.

The present invention still further relates to the combination of acompound of the invention together with a β.sub1.- toβ.sub4.-adrenoceptor agonists such as metaproterenol, isoproterenol,isoprenaline, albuterol, salbutamol, formoterol, salmeterol,terbutaline, orciprenaline, bitolterol mesylate, and pirbuterol; ormethylxanthanines including theophylline and aminophylline; sodiumcromoglycate; or muscarinic receptor (M1, M2, and M3) antagonist.

The present invention still further relates to the combination of acompound of the invention together with an insulin-like growth factortype I (IGF-1) mimetic.

The present invention still further relates to the combination of acompound of the invention together with an inhaled glucocorticoid withreduced systemic side effects, such as prednisone, prednisolone,flunisolide, triamcinolone acetonide, beclomethasone dipropionate,budesonide, fluticasone propionate, and mometasone furoate.

The present invention still further relates to the combination of acompound of the invention together with an inhibitor of matrixmetalloproteases (MMPs), i.e., the stromelysins, the collagenases, andthe gelatinases, as well as aggrecanase; especially collagenase-1(MMP-1), collagenase-2 (MMP-8), collagenase-3 (MMP-13), stromelysin-1(MMP-3), stromelysin-2 (MMP-10), and stromelysin-3 (MMP-11) and MMP-12.

The present invention still further relates to the combination of acompound of the invention together with other modulators of chemokinereceptor function such as CCR1, CCR2, CCR2A, CCR2B, CCR3, CCR4, CCR5,CCR6, CCR7, CCR8, CCR9, CCR10 and CCR11 (for the C—C family); CXCR1,CXCR3, CXCR4 and CXCR5 (for the C—X—C family) and CX₃CR1 for the C—X₃—Cfamily.

The present invention still further relates to the combination of acompound of the invention together with antiviral agents such asViracept, AZT, aciclovir and famciclovir, and antisepsis compounds suchas Valant.

The present invention still further relates to the combination of acompound of the invention together with cardiovascular agents such ascalcium channel blockers, lipid lowering agents such as statins,fibrates, beta-blockers, Ace inhibitors, Angiotensin-2 receptorantagonists and platelet aggregation inhibitors.

The present invention still further relates to the combination of acompound of the invention together with CNS agents such asantidepressants (such as sertraline), anti-Parkinsonian drugs (such asdeprenyl, L-dopa, Requip, Mirapex, MAOB inhibitors such as selegine andrasagiline, comP inhibitors such as Tasmar, A-2 inhibitors, dopaminereuptake inhibitors, NMDA antagonists, Nicotine agonists, Dopamineagonists and inhibitors of neuronal nitric oxide synthase), andanti-Alzheimer's drugs such as donepezil, tacrine, COX-2 inhibitors,propentofylline or metryfonate.

The present invention still further relates to the combination of acompound of the invention together with (i) tryptase inhibitors; (ii)platelet activating factor (PAF) antagonists; (iii) interleukinconverting enzyme (ICE) inhibitors; (iv) IMPDH inhibitors; (v) adhesionmolecule inhibitors including VLA-4 antagonists; (vi) cathepsins; (vii)MAP kinase inhibitors; (viii) glucose-6 phosphate dehydrogenaseinhibitors; (ix) kinin-B.sub1.- and B.sub2.-receptor antagonists; (x)anti-gout agents, e.g., colchicine; (xi) xanthine oxidase inhibitors,e.g., allopurinol; (xii) uricosuric agents, e.g., probenecid,sulfinpyrazone, and benzbromarone; (xiii) growth hormone secretagogues;(xiv) transforming growth factor (TGFβ); (xv) platelet-derived growthfactor (PDGF); (xvi) fibroblast growth factor, e.g., basic fibroblastgrowth factor (bFGF); (xvii) granulocyte macrophage colony stimulatingfactor (GM-CSF); (xviii) capsaicin cream; (xix) Tachykinin NK.sub1. andNK.sub3. receptor antagonists selected from the group consisting ofNKP-608C; SB-233412 (talnetant); and D-4418; (xx) elastase inhibitorsselected from the group consisting of UT-77 and ZD-0892; (xxi) TNFδconverting enzyme inhibitors (TACE); (xxii) induced nitric oxidesynthase inhibitors (iNOS) or (xxiii) chemoattractantreceptor-homologous molecule expressed on TH2 cells, (CRTH2antagonists).

The compounds of the present invention may also be used in combinationwith osteoporosis agents such as roloxifene, droloxifene, lasofoxifeneor fosomax and immunosuppressant agents such as FK-506, rapamycin,cyclosporine, azathioprine, and methotrexate.

The compounds of the invention may also be use in combination withexisting therapeutic agents for the treatment of osteoarthritis.Suitable agents to be used in combination include standard non-steroidalanti-inflammatory agents (hereinafter NSAID's) such as piroxicam,diclofenac propionic acids such as naproxen, flubiprofen, fenoprofen,ketoprofen and ibuprofen, fenamates such as mefenamic acid,indomethacin, sulindac, apazone, pyrazolones such as phenylbutazone,salicylates such as aspirin, COX-2 in inhibitors such as celecoxib,valdecoxib, rofecoxib and etoricoxib, analgesics and intraarticulartherapies such as corticosteroids and hyaluronic acids such as hyalganand synvisc and P2X7 receptor antagonists.

The compounds of the invention can also be used in combination withexisting therapeutic agents for the treatment of cancer. Suitable agentsto be used in combination include:

-   (i) antiproliferative/antineoplastic drugs and combinations thereof,    as used in medical oncology, such as alkylating agents (for example    cis-platin, carboplatin, cyclophosphamide, nitrogen mustard,    melphalan, chlorambucil, busulphan and nitrosoureas);    antimetabolites (for example antifolates such as fluoropyrimidines    like 5-fluorouracil and tegafur, raltitrexed, methotrexate, cytosine    arabinoside, hydroxyurea, gemcitabine and paclitaxel (Taxol®);    antitumour antibiotics (for example anthracyclines like adriamycin,    bleomycin, doxorubicin, daunomycin, epirubicin, idanibicin,    mitomycin-C, dactinomycin and mithramycin); antimitotic agents (for    example vinca alkaloids like vincristine, vinblastine, vindesine and    vinorelbine and taxoids like taxol and taxotere); and topoisomerase    inhibitors (for example epipodophyllotoxins like etoposide and    teniposide, amsacrine, topotecan and camptothecin);-   (ii) cytostatic agents such as antioestrogens (for example    tamoxifen, toremifene, raloxifene, droloxifene and iodoxyfene),    oestrogen receptor down regulators (for example fulvestrant),    antiandrogens (for example bicalutamide, flutamide, nilutamide and    cyproterone acetate), LHRH antagonists or LHRH agonists (for example    goserelin, leuprorelin and buserelin), progestogens (for example    megestrol acetate), aromatase inhibitors (for example as    anastrozole, letrozole, vorazole and exemestane) and inhibitors of    5α-reductase such as finasteride;-   (iii) Agents which inhibit cancer cell invasion (for example    metalloproteinase inhibitors like marimastat and inhibitors of    urokinase plasminogen activator receptor function);-   (iv) inhibitors of growth factor function, for example such    inhibitors include growth factor antibodies, growth factor receptor    antibodies (for example the anti-erbb2 antibody trastuzumab    [Herceptin™] and the anti-erbb1 antibody cetuximab [C225]), farnesyl    transferase inhibitors, tyrosine kinase inhibitors and    serine/threonine kinase inhibitors, for example inhibitors of the    epidermal growth factor family (for example EGFR family tyrosine    kinase inhibitors such as    N-(3-chloro-4-fluorophenyl)-7-methoxy-6-(3-morpholinopropoxy)quinazolin-4-amine    (gefitinib, AZD1839),    N-(3-ethynylphenyl)-6,7-bis(2-methoxyethoxy)quinazolin-4-amine    (erlotinib, OSI-774) and    6-acrylamido-N-(3-chloro-4-fluorophenyl)-7-(3-morpholinopropoxy)quinazolin-4-amine    (CI 1033)), for example inhibitors of the platelet-derived growth    factor family and for example inhibitors of the hepatocyte growth    factor family;-   (v) antiangiogenic agents such as those which inhibit the effects of    vascular endothelial growth factor, (for example the anti-vascular    endothelial cell growth factor antibody bevacizumab [Avastin™],    compounds such as those disclosed in International Patent    Applications WO 97/22596, WO 97/30035, WO 97/32856 and WO 98/13354)    and compounds that work by other mechanisms (for example linomide,    inhibitors of integrin αvβ3 function and angiostatin);-   (vi) vascular damaging agents such as Combretastatin A4 and    compounds disclosed in International Patent Applications WO    99/02166, WO00/40529, WO 00/41669, WO01/92224, WO02/04434 and    WO02/08213;-   (vii) antisense therapies, for example those which are directed to    the targets listed above, such as ISIS 2503, an anti-ras antisense;-   (viii) gene therapy approaches, including for example approaches to    replace aberrant genes such as aberrant p53 or aberrant BRCA1 or    BRCA2, GDEPT (gene-directed enzyme pro-drug therapy) approaches such    as those using cytosine deaminase, thymidine linase or a bacterial    nitroreductase enzyme and approaches to increase patient tolerance    to chemotherapy or radiotherapy such as multi-drug resistance gene    therapy; and-   (ix) immunotherapy approaches, including for example ex-vivo and    in-vivo approaches to increase the immunogenicity of patient tumour    cells, such as transfection with cytokines such as interleukin 2,    interleukin 4 or granulocyte-macrophage colony stimulating factor,    approaches to decrease T-cell anergy, approaches using transfected    immune cells such as cytokine-transfected dendritic cells,    approaches using cytokine-transfected tumour cell lines and    approaches using anti-idiotypic antibodies.

The invention will now be further illustrated by reference to thefollowing examples. In the examples the Nuclear Magnetic Resonance (NMR)spectra were measured on a Varian Unity Inova 300 or 400 MHzspectrometer and the Mass Spectrometry (MS) spectra measured on anAgilent MSD spectrometer Where necessary, the reactions were performedunder an inert atmosphere of either nitrogen. Chromatography wasgenerally performed using Matrex Silica 60® (35-70 micron) or ProlaboSilica gel 60® (35-70 micron) suitable for flash silica gelchromatography. High performance liquid-chromatography purification wasperformed using a Gilson Auto-Purification System. The abbreviationsm.p. and DMSO used in the examples stand for melting point and dimethylsulphoxide respectively. Compounds were named using ACD/labs-6.0 namingprogramme.

EXAMPLE 15-[[(2,3-Difluorophenyl)methyl]thio]-7-[[2-hydroxy-1-(hydroxymethyl) 1methylethyl]amino]-thiazolo[4,5-d]pyrimidin-2(3H)-one a)6-Amino-2-[[(2,3-difluorophenyl)methyl]thio]-4(3H)-pyrimidinone

4-Amino-6-hydroxy-2-mercaptopyrimidine monohydrate (7.1 g) was addedportion wise to a stirred suspension of 60% sodium hydride (2.4 g) indry N,N-dimethylformamide (70 ml). After 1 hour a solution of2,3-Difluorobenzyl bromide (10 g) in dry N,N-dimethylformamide (10 ml)was added. Stirred over weekend at room temperature. Poured on toice/water and the precipitate was collected by filtration to give 9.6 gof product. 81% yield.

MS (APCI) (+ve) 270 (M+H, 94%)

b)4Amino-2-[[(2,3-difluorophenyl)methyl]thio]-1,6-dihydro-6-oxo-5-pyrimidinylester thiocyanic acid

The product from step (a) (28 g) and potassium thiocyanate (40.5 g) inN,N-dimethylformamide (583 ml) were heated together at 65° C. Pyridine(14.5 ml) was added and the solution cooled to 5° C. Bromine (5.0 ml)was added slowly and the reaction mixture stirred for 2 hours at 5-10°C. The reaction mixture was poured onto ice water (4200 ml), stirred for1 hour and the solid was collected by filtration, washed with water andether, to give 24 g of product. 70% yield.

MS (APCI) (+ve) 327 (M+H)

c)2-Amino-5-[[(2,3-difluorophenyl)methyl]thio]-thiazolo[4,5-d]pyrimidin-7(6H)-one

A mixture of the product from step (b) (12.1 g), N,N-dimethylformamide(70 ml) and water (20 ml) was heated to 120° C. for 24 hours. Acolourless solid precipitated from the solution, which was allowed tocool, and the solid collected by filtration to give 8.3 g of product.70% yield.

MS (APCI) (+ve) 327 (M+H)

d)7-Chloro-5-[[(2,3-difluorophenyl)methyl]thio]-thiazolo[4,5-d]pyrimidin-2-amine

The product of step (c) (10.0 g) was suspended in phosphoryl chloride(55 ml). N,N-dimethylaniline (5.5 ml) added slowly and reaction mixtureheated at reflux for 2 hours. Allowed to cool, then poured on to icewith vigorous stirring; temperature was not allowed to go above 45° C.(ice added). After approximately 20 minutes the temperature stabilizedat 30° C. The solid that formed was collected by filtration and washedwith water. Purified by column chromatography (EtOAc to 5% MeOH inEtOAc) to give 3.34 g of product. 31% yield.

MS: APCI (+ve) 345 (M+H)

e)2-[[2-Amino-5-[[(2,3-difluorophenyl)methyl]thio]thiazolo[4,5-d]pyrimidin-7-yl]amino]-2-methyl-1,3-propanediol

The product from step (d) (1.5 g) was suspended in NMP (10 ml), thenHunigs base (1.5 ml) and 2-Amino-2-methylpropanediol (1.37 g) added.Reaction mixture heated to 110° C. under N₂ for 4 hrs. A further aliquotof 2-Amino-2-methylpropanediol (0.685 g) was added and mixture heated at110° C. for 5 hrs. Mixture poured in to water (400 ml) and solid wascollected by filtration. Purified by column chromatography (EtOAc:Methanol (95:5)) to give 0.756 g of product. 42% yield.

MS: APCI (+ve) 414 (M+H)

f)2-[[2-Chloro-5-[[(2,3-difluorophenyl)methyl]thio]thiazolo[4,5-d]pyrimidin-7-yl]amino]-2-methyl-1,3-propanediol

The product from step (e) (0.485 g) was suspended in conc.HCl (18 ml)which was then cooled to 15° C. A mixture of water (15 ml) andacetonitrile (25 ml) added to give a solution. Cooled to 5° C. and asolution of sodium nitrite (0.162 g) in water (1 ml) added drop-wise.Stirred at 5° C. for several hours then allowed to warm overnight.Solution cooled to −10° C. and neutralized with ammonia, thenconcentrated in vacuo. The yellow precipitate was collected byfiltration and washed with water. Dried in vacuo to give 0.339 g ofproduct. 67% yield.

MS: APCI (+ve) 433 (M+H)

g)2-[[5-[[(2,3-Difluorophenyl)methyl]thio]-2-methoxythiazolo[4,5-d]pyrimidin-7-yl]amino]-2-methyl-1,3-propanediol

The product from step (f) (0.339 g) was suspended in methanol (32 ml).Potasium hydroxide (0.088 g) added and mixture stirred at 50° C. for 20minutes. Neutralised with 2N HCl and solvents removed in vacuo to givean orange residue. Water added to remove inorganics and the yellow solidwas collected by filtration to give 0.3 g of desired product. 90% yield.

MS: APCI (+ve) 429 (M+H)

h)5-[[(2,3-Difluorophenyl)methyl]thio]-7-[[2-hydroxy-1-(hydroxymethyl)-1-methylethyl]amino]-thiazolo[4,5-d]pyrimidin-2(3H)-one

The product from step (g) (0.3 g) was suspended in a mixture of dioxan(50 ml) and conc.HCl (1 ml). Water (1 ml) was added and the resultantsolution heated at 60° C. for 12 hours. Allowed to stand over weekend.Solvents removed in vacuo and residue taken up in water. Yellowprecipitate collected by filtration and washed with water. Purifiedusing prep. Hplc Acetonitrile: 0.1% ammonium acetate (90:10 to 95:5)over 25 minutes to give 0.063 g of the desired product. 22% yield.

MS: APCI (+ve) 415 (M+H)

¹H NMR: δ (DMSO) 1.25 (3H, s), 3.54-3.66 (4H, m), 4.39 (2H, s),4.65-4.69 (2H, t), 6.34 (1H, s), 7.12-7.20 (1H, m), 7.29-7.41 (2H, m),12.43 (1H, s). mp 230-233° C.

EXAMPLE 25-[[(2,3-Difluorophenyl)methyl]thio]-7-[[2-hydroxy-1-(hydroxymethyl)-1-methylethyl]amino]-thiazolo[4,5-d]pyrimidin-2(3H)-one,monosodium salt

The product from Example 1, step (h) (0.87 g) was suspended in water (80ml), 1.0M sodium hydroxide (3.0 ml) added, then methanol (15 ml), andthe mixture heated on a steam bath. When dissolution was almostcomplete, the mixture was filtered hot and the filtrate chilledovernight to give a fluffy white precipitate after filtration. This wasdried in a vacuum oven overnight at 50° C. (0.60 g).

MS: APCI (+ve) 415 (M+H)

¹H NMR: δ (DMSO) 1.23 (3H, s), 3.47-3.58 (4H, m), 4.37 (2H, s), 4.94(2H, t), 5.29 (1H, s), 7.14 (1H, m), 7.31 (1H, m), 7.35 (1H, m). mp 238°C. (dec.)

Pharmacological Data

Ligand Binding Assay

[¹²⁵I]IL-8 (human, recombinant) was purchased from Amersham, U.K. with aspecific activity of 2,000 Ci/mmol. All other chemicals were ofanalytical grade. High levels of hrCXCR2 were expressed in HEK 293 cells(human embryo kidney 293 cells ECACC No. 85120602) (Lee et al. (1992) J.Biol. Chem. 267 pp 16283-16291). hrCXC2 cDNA was amplified and clonedfrom human neutrophil mRNA. The DNA was cloned into PCRScript(Stratagene) and clones were identified using DNA. The coding sequencewas sub-cloned into the eukaryotic expression vector RcCMV (Invitrogen).Plasmid DNA was prepared using Quiagen Megaprep 2500 and transfectedinto HEK 293 cells using Lipofectamine reagent (Gibco BRL). Cells of thehighest expressing clone were harvested in phosphate-buffered salinecontaining 0.2%(w/v) ethylenediaminetetraacetic acid (EDTA) andcentrifuged (200 g, 5 min.). The cell pellet was resuspended in ice coldhomogenisation buffer [10 mM HEPES (pH 7.4), 1 mM dithiothreitol, 1 mMEDTA and a panel of protease inhibitors (1 mM phenyl methyl sulphonylfluoride, 2 μg/ml soybean trypsin inhibitor, 3 mM benzamidine, 0.5 μg/mlleupeptin and 100 μg/ml bacitracin)] and the cells left to swell for 10minutes. The cell preparation was disrupted using a hand held glassmortar/PTFE pestle homogeniser and cell membranes harvested bycentrifugation (45 minutes, 100,000 g, 4° C.). The membrane preparationwas stored at −70° C. in homogenisation buffer supplemented withTyrode's salt solution (137 mM NaCl, 2.7 mM KCl, 0.4 mM NaH₂PO₄),0.1%(w/v) gelatin and 10%(v/v) glycerol. All assays were performed in a96-well MultiScreen 0.45 μm filtration plates (Millipore, U.K.). Eachassay contained ˜50 pM [¹²⁵I]IL-8 and membranes (equivalent to ˜200,000cells) in assay buffer [Tyrode's salt solution supplemented with 10 mMHEPES (pH 7.4), 1.8 mM CaCl₂, 1 mM MgCl₂, 0.125 mg/ml bacitracin and0.1%(w/v) gelatin]. In addition, a compound of formula (I) according tothe Examples was pre-dissolved in DMSO and added to reach a finalconcentration of 1% (v/v) DMSO. The assay was initiated with theaddition of membranes and after 1.5 hours at room temperature themembranes were harvested by filtration using a Millipore MultiScreenvacuum manifold and washed twice with assay buffer (without bacitracin).The backing plate was removed from the MultiScreen plate assembly, thefilters dried at room temperature, punched out and then counted on aCobra γ-counter. The compound of formula (I) has an IC₅₀ value of lessthan (<) 10 μM.

Intracellular Calcium Mobilisation Assay

Human nutrophils were prepared from EDTA-treated peripheral blood, aspreviously described (Baly et al. (1997) Methods in Enzymology 287 pp70-72), in storage buffer [Tyrode's salt solution (137 mM NaCl, 2.7 mMKCl, 0.4 mM NaH₂PO₄) supplemented with 5.7 mM glucose and 10 mM HEPES(pH 7.4)].

The chemokine GROα (human, recombinant) was purchased from R&D Systems(Abingdon, U.K.). All other chemicals were of analytical grade. Changesin intracellular free calcium were measured fluorometrically by loadingneutrophils with the calcium sensitive fluorescent dye, fluo-3, asdescribed previously (Merritt et al. (1990) Biochem. J. 269, pp513-519).Cells were loaded for 1 hour at 37° C. in loading buffer (storage bufferwith 0.1% (w/v) gelatin) containing 5 μM fluo-3 AM ester, washed withloading buffer and then resuspended in Tyrode's salt solutionsupplemented with 5.7 mM glucose, 0.1% (w/v) bovine serum albumin (BSA),1.8 mM CaCl₂ and 1 mM MgCl₂. The cells were pipetted into black walled,clear bottom, 96 well micro plates (Costar, Boston, U.S.A.) andcentrifuged (200 g, 5 minutes, room temperature).

A compound of formula (I) according to the Examples was pre-dissolved inDMSO and added to a final concentration of 0.1% (v/v) DMSO. Assays wereinitiated by the addition of an A₅₀ concentration of GROα and thetransient increase in fluo-3 fluorescence (λ_(Ex)=490 nm and λ_(Em)=520nm) monitored using a FLIPR (Fluorometric Imaging Plate Reader,Molecular Devices, Sunnyvale, U.S.A.).

The compound of formula (I) was tested and found to be an antagonist ofthe CXCR2 receptor in human neutrophils.

1. A monosodium salt of the compound of formula (I):


2. A process for the preparation of the monosodium salt of a compound of formula (I) of claim 1, which comprises reaction of a compound of formula (II):

where R is C₁₋₆ alkyl with an acid, and thereafter forming a monosodium salt.
 3. A pharmaceutical composition comprising the monosodium salt of the compound of Formula I of claim 1 and a pharmaceutically acceptable adjuvant, diluent, or carrier. 